in reply to appending to a file

Not checking the return value from things like chdir, opendir, or open certainly could be considered stupid.

The cake is a lie.
The cake is a lie.
The cake is a lie.

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Re^2: appending to a file
by dwm042 (Priest) on Mar 19, 2009 at 20:16 UTC
    fletch++

    To give a more direct example of what Fletch is talking about, do you know what happens in this piece of code if the change directory does not exist?

    my $dir = "/my/working/directory";
chdir ( $dir );
system ("rm -rf *");

    [download]
[reply]
[d/l]
      This removes everything in the dir.
[reply]
Re^2: appending to a file
by lomSpace (Scribe) on Mar 19, 2009 at 16:56 UTC

    I checked the return values of chdir with Dumper. $in gives me
    a glob memory address. I know that I am in the correct dir
    because my regex matches the file names.

[reply]
      It will always give you a glob memory address
      #!/usr/bin/perl --
use Data::Dumper;
use strict;
use warnings;
opendir my $dh, "doesnotexist.mustnotexist";
print Dumper( $dh);
__END__
$VAR1 = \*{'::$dh'};

D:\dev\misc>
D:\dev\misc>perl
#!/usr/bin/perl --
use Data::Dumper;
use strict;
use warnings;

for my $dir( "doesnotexist.mustnotexist", "."){
    opendir my $dh, $dir;
Parentheses missing around "my" list at - line 7.
    print "dir $dir ", Dumper( $dh);
}
__END__
dir doesnotexist.mustnotexist $VAR1 = \*{'::$dh'};
dir . $VAR1 = \*{'::$dh'};

      [download]
      system calls can fail for any reason
[reply]
[d/l]

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